bugfix: core: Text-browsers causing ZT to freeze.

Temporarily unsetting TERM environ so text-browsers aren't detected.

This results in an exception which displays an error for text-browsers.

Fixes #1475.

tests/core/test_core.py

@@ -427,6 +427,8 @@ def test_open_in_browser_success(
     ) -> None:
         # Set DISPLAY environ to be able to run test in CI
         os.environ["DISPLAY"] = ":0"
+        # Set TERM environ to be able to check text-browsers
+        os.environ["TERM"] = "xterm-256color"
         mocked_report_success = mocker.patch(MODULE + ".Controller.report_success")
         mock_get = mocker.patch(MODULE + ".webbrowser.get")
         mock_open = mock_get.return_value.open
@@ -447,6 +449,7 @@ def test_open_in_browser_fail__no_browser_controller(
         self, mocker: MockerFixture, controller: Controller
     ) -> None:
         os.environ["DISPLAY"] = ":0"
+        os.environ["TERM"] = "xterm-256color"
         error = "No runnable browser found"
         mocked_report_error = mocker.patch(MODULE + ".Controller.report_error")
         mocker.patch(MODULE + ".webbrowser.get").side_effect = webbrowser.Error(error)

zulipterminal/core.py

@@ -410,6 +410,8 @@ def open_in_browser(self, url: str) -> None:
         try:
             # Checks for a runnable browser in the system and returns
             # its browser controller, if found, else reports an error
+            term = os.environ.get("TERM")  # Saving the original value
+            del os.environ["TERM"]  # Temporarily deleting variable
             browser_controller = webbrowser.get()
             # Suppress stdout and stderr when opening browser
             with suppress_output():
@@ -424,6 +426,8 @@ def open_in_browser(self, url: str) -> None:
                     [f"The link was successfully opened using {browser_name}"]
                 )
         except webbrowser.Error as e:
+            if isinstance(term, str):
+                os.environ["TERM"] = term  # resetting
             # Set a footer text if no runnable browser is located
             self.report_error([f"ERROR: {e}"])